Sci-tech

China plans on double-decker bullet trains

Top speed of 350km/h not a problem: analysts

Recently revealed pictures of an alleged conceptual model of China's next-generation high-speed double-decker train have made quite a splash, with Chinese researchers positively speculating that it is "no problem" to develop such a 350-kilometers-per-hour train.

The pictures were picked up by Chinese media including the Science and Technology Daily, an official paper administered by theMinistry of Science and Technology, and the model, according to the paper's report, was made by the Chinese Academy of Sciences (CAS).

Although there is no further information on the conceptual model mentioned in the report, the paper cited Zhang Weihua, a professor at Chengdu-based Southwest Jiaotong University, as saying that China, just like traditional high speed train powerhouses such as France and Germany, is advocating the development of double-decker bullet trains in a bid to expand the vehicles' ridership and make them run more economically and efficiently.

"There won't be any problem to run these double-decker trains at a speed of 350 kilometers per hour, equivalent to the country's single-deckers, as long as we solve the design technique problems related to lowering the center of gravity on the coaches, increasing the coaches' capacity, and so on," said Zhang, who also served as the head of the State Key Laboratory of Traction Power from 2001 to 2014. Safety issues will not be a problem, he argued.

And Zhang suggested that by adopting independently revolving wheels, both design goals could be reached.

According to the paper, the most critical challenge lies in that the high-speed double-decker vehicle would likely lose stability from the centrifugal force on fast turns.

However, Zhang stated that such an issue could be solved as the center of gravity can be lowered.

The CAS publicity department, when reached by the Global Times on Tuesday, did not reveal which units were in charge of future train development.

Yang Ying, deputy chief engineer of the company, said that it can run at a speed of 160 kilometers per hour, and such a speed can be made faster through system upgrading.

According to the official website of the Europe-based makers of rail equipment Alstom, the company's Avelia Euroduplex to date is the only double-decker in the world running above 300 kilometers per hour.

And thanks to its two-floor formation, an eight-car (200 meters) Avelia Euroduplex holds up to 40 percent more passengers than a single-deck train of equivalent length and similar gauge, enabling it to carry up to 1,268 passengers at 320 kilometers per hour, the company said.

Such trains operate in France, Germany, Switzerland, Spain and Luxembourg.

Japan's E4 series double-decker carriages, which debuted in 1997, have a seating capacity of 1,634, the largest in the world among high-speed trains.

The Japanese double-deckers initially ran on the Tohoku Shinkansen Line connecting Tokyo and Aomori, but the service ended in 2012, the Japan Times reported. The top speed for the Japanese double-decker reached 240 kilometers per hour, Science and Technology Daily reported.

"China is technically ready for designing and manufacturing such double-decker high-speed trains," Jia Limin, a leading expert in high-speed trains and a professor at Beijing Jiaotong University, told the Global Times on Tuesday.

Whether or not to manufacture such trains depends on the national railway authorities' overall planning and calculation, he noted. Such a pricy upgrade must bring back reasonable profits, Jia said.

Jia also pointed out that the actual market needs do exist on busy routes in the eastern plains, including lines such as Beijing-Shanghai and Shanghai-Hangzhou, where it is not uncommon for tickets to sell out.

The Beijing-Shanghai high-speed railway began operating in June 2011. By June 2018, it had transported 825 million passengers, or 10 percent of total passenger flow across all high-speed railways in the country.

China Railway Corporation said it will put 17 350-kilometers-per-hour bullet trains into operation in 2019, Global Times previously reported.

Jia suggested running such double-decker carriages during peak holidays and switching to regular single-decker could be a workable mode for the operators.

However, some experts also urged caution, believing such an expensive and ambitious plan should not be prioritized.

Sun Zhang, a railway expert and professor at Shanghai Tongji University, told the Global Times that while it was legitimate to prepare double-decker technology for the long term, it should not be top priority in the short run.

That top priority, according to Sun, should be "a regular single-decker high speed system in the less developed middle and western parts of the country."